diff --git a/python/paddle/fluid/layers/nn.py b/python/paddle/fluid/layers/nn.py
index dde0e6f3b3b05879dc40391198dca9afef1c6052..110e6d5ab236a9baa645ad02ba69c59673152024 100644
--- a/python/paddle/fluid/layers/nn.py
+++ b/python/paddle/fluid/layers/nn.py
@@ -3020,7 +3020,8 @@ def sequence_pad(x, pad_value, maxlen=None, name=None):
 
             x = fluid.layers.data(name='y', shape=[10, 5],
                              dtype='float32', lod_level=1)
-            pad_value = fluid.layers.assign(input=numpy.array([0]))
+            pad_value = fluid.layers.assign(
+                input=numpy.array([0], dtype=numpy.float32))
             out = fluid.layers.sequence_pad(x=x, pad_value=pad_value)
     """